On Mon, 25 Feb 2019 21:52:46 -0800
Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote:
> On Mon, Feb 25, 2019 at 11:36:40AM -0500, Steven Rostedt wrote:
> > On Sun, 24 Feb 2019 21:11:59 -0800
> > ira.weiny@xxxxxxxxx wrote:
> >
> > > INGENIC JZ4780 DMA Driver
> > > M: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@xxxxxxxxxx>
> > > diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
> > > index e742a6a2c138..d5cd90fecda7 100644
> > > --- a/drivers/infiniband/core/mad.c
> > > +++ b/drivers/infiniband/core/mad.c
> > > @@ -3,7 +3,7 @@
> > > * Copyright (c) 2005 Intel Corporation. All rights reserved.
> > > * Copyright (c) 2005 Mellanox Technologies Ltd. All rights reserved.
> > > * Copyright (c) 2009 HNR Consulting. All rights reserved.
> > > - * Copyright (c) 2014 Intel Corporation. All rights reserved.
> > > + * Copyright (c) 2014,2018 Intel Corporation. All rights reserved.
> > > *
> > > * This software is available to you under a choice of one of two
> > > * licenses. You may choose to be licensed under the terms of the GNU
> > > @@ -51,6 +51,41 @@
> > > #include "opa_smi.h"
> > > #include "agent.h"
> > >
> > > +static void create_mad_addr_info(struct ib_mad_send_wr_private *mad_send_wr,
> > > + struct ib_mad_qp_info *qp_info,
> > > + u32 *dlid, u8 *sl, u16 *pkey, u32 *rqpn,
> > > + u32 *rqkey)
> > > +{
> >
> > Instead of passing in a bunch of addresses, you may be able to pass in
> > the entry structure directly.
> >
> > struct trace_event_raw_ib_mad_send_template *entry
> >
> > (defined from DECLARE_EVENT_CLASS(name, ...
> >
> > struct trace_event_raw_##name .. )
> >
> > And just assign everything as:
> >
> > entry->dlid = x, ...
>
> raw_tracepoint requires all args to fit into u64.
> bpf prog cannot access it otherwise.
> Also struct by value is pretty slow on some archs.
> Pointer to struct is always preferred.
I meant passing in the pointer, not the value. It wouldn't make sense
otherwise, because the entire point of create_mad_addr_info(), is to
update the __entry structure. How would passing in the value do that?
Instead of:
+ create_mad_addr_info(wr, qp_info,
+ &__entry->dlid, &__entry->sl,
+ &__entry->pkey, &__entry->rqpn,
+ &__entry->rqkey);
You do:
create_mad_addr_info(wr, qp_info, __entry);
And then in that function you assign the values directly to the structure.
-- Steve
